A microsomal galactose oxidizing system (M.G.O.S.), identified in this laboratory, will be further purified, characterized, and classified according to its reaction mechanism. The product of the reaction, galactonic acid or its lactone precursor, will be tested as a potential inhibitory metabolite of lysosomal, microsomal, and glycolytic enzymes. The hypothesis that lysosomes participate in the process of hormone-mediated enzyme induction will be further investigated utilizing the starved-refed rat, diabetic rats, the genetically obese mouse, and the beige mutant mouse. In vitro studies are planned with cultured primary rat hepatocytes and the mouse fibroblast subline, 3T3-L1, which differentiates into adipocytes. Nuclear RNA synthesis studies will be conducted to augment the previous probes of the basic hypothesis. Finally, an isozyme of nucleoside diphosphate kinase has been discovered to be a microtubule-associated protein. During the grant period the kinase will be purified, and its properties and possible regulatory role in microtubule assembly mechanism will be assessed.